Soldiers, sportsmen, and other firearm users sometimes find it desirable to include or attach one or more accessories of various kinds on a firearm. Some common accessories include sights, scopes, or other aiming devices or enhancements; flashlights, infrared lights, or other illumination devices; or other accessories to meet the needs of the user. Many of these, as well as other accessories for firearms, require a supply of electricity, such as a battery, to operate correctly or optimally.
A typical solution is the inclusion of a battery housed within the accessory device itself for provision of sufficient electrical power to operate the device. Unfortunately, many batteries are relatively heavy. Similarly, the batteries can be positioned inconveniently, for example, along the length of the barrel of the firearm, due to the mounting position of the accessory device. Such disadvantageous battery positioning can unsettle the desirable neutral balance of the firearm and can require the user to compensate for the additional weight disposed along the barrel when aiming the firearm. As a demonstrative example of the serious consequences of such unsettling, the additional weight of the battery within the accessory may cause the user to miss an intended target when firing, which can be disastrous for the user in a combat situation.
In an attempt to ameliorate the undesirable effect on the neutral balance of the firearm, accessory manufacturers have kept battery sizes small, thereby reducing the overall weight of the accessory. Although smaller batteries lessen the detrimental effect on the neutral balance of the firearm, they do so at the cost of battery life. Smaller, lighter batteries sometimes have less capacity and/or cannot provide power to the accessory for as long a time as a larger, heavier battery. In some cases, especially where the accessory is considered to be essential and/or where access to replacement batteries or electricity for recharging the battery is limited or non-existent, heavier batteries with longer life are used despite the detrimental effects on the balance of the firearm.
Another problem with battery operated firearm accessories is that each accessory, as provided by different manufacturers or even by the same manufacturer, can include circuitry designed to use a supply of electrical power having particular characteristics such as a specific voltage or current, thereby necessitating a variety of battery configurations. Replacing or recharging the batteries can be difficult and/or expensive due to the unique requirements of each accessory device.